Screw driver with adjustable bit



April 1958 A. M. OLIVER] SCREW DRIVER WITH ADJUSTABLE BIT 3 Sheets-Sheet 1 Filed April 4, 1955 7/Z. @(fs'veyur) April 29,1958 A. M. QLIVEJW]! 9 3 SCREW DRIVER WITH ADJUS'IABLEI BIT Filed April 4, .1955 3 Sheet$--Sheet 2 United States PatentO SCREW DRIVER WITH ADJUSTABLE BIT Anthony M. Oliveri, Chicago, Ill.

Application April 4, 1955, Serial No. 498,969

6 Claims. (Cl. 145-50) This invention relates to a screw driver and in particular to a screw driver having a blade which is adjustable to fit the screw slot over a range of slot Widths.

Screw drivers commonly found in the art comprise a cylindrical shaft at one end of which is mounted a suitable handle, and at the other end of which is formed a screw slot engaging blade. Generally each screw driver is provided with a blade adapted for cooperation with a specific width screw slot; where screws having different Width slots are to be used, a plurality of screw drivers each having a blade adapted for use with one width slot are required. Often a screw driver having the proper blade is not available and one of the wrong size is used with resulting deformation of the screw slot and, often, improper installation of the screw.

The principal feature of this invention is the provision of a new and improved screw driver having a blade adjustable to fit slots of different widths.

Another feature of the invention is the provision of a screw driver having a blade of adjustable thickness comprising a plurality of relatively movable tapered members.

A further feature is the provision of such a screw driver wherein the tapered members comprise juxtaposed tapered disks mounted for relative rotation. A still further feature is that said disks are rotatable oppositely equiangularly to provide parallel screw engaging portions.

' A yet further feature of the invention is the provision of a screw driver having rotatable blade forming disks and means for controlling the relative angular position of said disks, including spring means to urge rotation of the disks to their thickest blade forming relationship and manually operable means for rotating the disks to their thinnest blade forming relationship.

Other features and advantages of this invention-will be apparent from the following description taken in connec-' tion with the accompanying drawings wherein:

Fig. 1 is a side view of a screw driver embodying the invention;

Fig. 2 is an enlarged, broken longitudinal sectional view thereof:

Fig. 3 is an enlarged fragmentary sectional view thereof taken at right angles to the view of Fig. 2 showing the parts in one position;

Fig. 4 is a view similar to Fig. 3 showing the parts in another position;

Fig. 5 is a transverse sectional view taken substantially along the line '5--5 of Fig. 3;

Fig. 6 is a transverse sectional view taken substantially Fig. 10 is a fragmentary longitudinal sectional view of a modified form of screw driver;

Fig. 11 is a fragmentary longitudinal sectional view taken at right angles to the view of Fig. 10;

'amount. Thickness adjusting mechanism 14 is provided with means for rotatably mounting the disks 13a and yield 2,832,335 Patented Apr. 29, 1958 Fig. 12 is a fragmentary side view of the blade end of the screw driver of Fig. 10;

Fig. 13 is an end view looking from the left of Fig. 10;

Fig. 14 is an elevational view of the disk of the screw driver of Fig. 10; and

Fig. 15 is a fragmentary longitudinal sectional view of a screw driver having an electrical insulating handle.

Referring now to Figs. 1-9 of the drawings, a screw driver embodying the invention is shown and includes a tubular shaft 10 at one end of which is: fixedly secured a suitable handle 11. At the opposite end of the tubular shaft is fixedly secured a head 12 with a slot 12a in the outer end thereof through which projects a screw slot engaging blade generally designated 13.

A blade thickness adjusting mechanism, generally designated 14, which cooperates with the blade 13 to alter on the shaft 10 and may be moved longitudinally to op erate lever 15. Blade 13, mechanism 14 and lever 15 are interrelated functionally so that movement of the projecting portion of the lever toward the head 12 causes the portion of the blade 13 projecting from the head 12 to have a reduced thickness so that it may be readily inserted into the screw slot. Upon release of the lever 15, mechanism 14 causes the width of the projecting portion of the blade to increase until the blade sides engage the sides of the screw slot assuring good contact therebetween.

As best seen in Figs. 2 and 3, blade 13 comprises a pair of similar tapered disks 13a mounted in juxtaposition so as to have mutually engaging faces 13a. .As best seen in Fig. 8 each disk is provided with a central hub receiving opening 13a". The disks 1311 project through transverse slot 12:: in the outer end of the head 12 which is telescopically mounted on the end of the shaft 10 and secured thereon by suitable means such as cars 10b'on the shaft engaging openings 12b in the head. As best seen in Fig. 2 the ends of the slot 12:: are made arcuate so as to be complementary to the periphery of the disks acting as a limiting abutment allowing the disks to project through the slot no more than a ingly maintaining them in contact with the ends of transverse slot 12a. For this purpose a pair of hubs 17 are provided, each hub having a cylindrical portion 17a and a boss 17b of square cross section adapted snugly to fit the disk opening 12a". The cylindrical portion 17a is provided with a circumferential groove 17a and with a pair of longitudinal outwardly opening recesses 17a" and 17a. A yoke 18 is movably mounted in the shaft 10, having a cylindrical portion 18a carried longitudinally, reciprocably between a pair of chordal supports 19 extending transversely interiorly of the shaft 10 at a point spaced from the head end. Depending from yoke cylindrical portion 18a is a U-shaped portion 18b. The cute rend of each of the legs of the U-shaped portion is provided "with an outwardly opening recess havinga w idth comparable to the inner diameter of hub groove" 17a so that the hub may be journalled therein. The

spacing between the legs of portion 18b is such that when one disk 13:: mounted on one hub 17 is journalled in recess 18b ofone leg and the other disk mounted on the" other is journalled in the other leg, disk faces 13 suitable prescribed are juxtaposed; Mounted on the cylindrical portion 18a tween the end of the spring'and the supports. This spring. acts to urge-the yoke 18 and the disks thereon outwardly so that the periphery of the disks will be normally maintained in abutment with the ends of the slot 12a while allowing inward yielding. Such arrangement allows for economy in manufacture as accurate spacing of the axis'of rotation of the disks from the head slot 12ais obtained automatically notwithstanding rough tolerances-in the position of the supports 19.

The means forrotating the disks relative to each other includesashortloop arm 21 and a long'loop arm 22. The loop arms are similarin construction except that the longitudinally extendingportions 21a of the short arm 21 are relatively short, extending from the hub 17 to a. point short of the lever 15, while the longitudinal portions 22a of-the long arm 22 extend from the hub to the lever 15. The longitudinal portions of the arms are connected at their inner ends by a transversely extending connecting portion- 21b in the short arm and 22b in the long arm. A tension spring 23 interconnects the connecting portions 21b and 22b to urge them together, thus tending to position the loop arms 21 and 22 relative to each other. At the ends of the loop arms, opposite the connecting portions, laterally inwardly directed ends 21c and 220 are formed in the short and long arms respectively. As seen in ,Fig. 7, the ends 220 of the long loop arm extend inwardly oppositely at a clockwise angle from the plane of the longitudinal and connecting portions; short loop ends 21c extend inwardly similarly except they are directed angularly counterclockwise from the plane of portions 21a and 21b, the difference in angularity being provided to allow a cross-over relationship between the two loop arm as maybest be seen in Fig. 2.

Recesses 17a" of hubs 17 arespaced from the longitudinal axis of the hubs on a radius extending angularly from a plane taken at right angles to the disk 13a when mounted on the hub with such plane passing through the thinnest and thickest sections of the disk. Recesses 17a are similarly positioned except that they are on a radius 180 from the radius on which recesses 17a lie. In the embodiment shown, and as best seen in Figs. 2', 3, 4 and 5, loop arms ends 210 are received in recesses 17a" and ends 22c are received in recesses 17a. As tension spring 2 3 tends to urge loop arm 21 toward the handle end of the screw driver, the hub and disk assembly is rotated, to the position wherein the recess17a" is closest tothehandle endmof the screw driver, sothat thev thickest.

portion of the disk projects from the head, as, seen in Figs. 2 and 3. It may be seen at this point also that spring 23 urges long loop arm 22 longitudinally away from the handle end, thus cumulatively urging this positioning of the disks. Because of the angular extension of arm ends 210 and 22c relative to the planes of arm portions 21a and 21b and portions 22a and 22b respectively and the disposition of the hub recesses angularly" screw driver will move the hook portion 15a toward the handle end and cause the long loop arm 22 to rotate the hubs and disks so that the thinnest portion. will project through the slot 12a as shown in Fig. 4. As recesses 17a! and 1711" are disposed on oppositesidesof and spaced equally from a plane drawn throughthe axis 4 of rotation of the hubs and extending longitudinally of theshaft 10 they are rotated equiangularly in opposite directions. Such rotation causes the disks to have screw slot engaging portions which are parallel at all times, thus providing improved fit and reducing any tendency to damage the slot walls.

The operation of my screw driver is readily manually effected by moving the actuating ring 16 toward the head end of the shaft so as to pivot the lever 15 and draw the long loop arm 22.1ongitudinally toward the handle. end of the screw driver. As previously indicated, this causes rotation of both disks 13a so that the thinnest portions project throughthe slot 12aof. the head. 7 With the. disks so arranged, they, constituting the blade portion of the screw driver, are inserted into the slot of the screw to be manipulated. Actuating member 16 is then released and tension spring 23 acts on short arm 21 to move it longitudinally toward the handle end of the screw driver and onthe long arm 22 to move it longitudinally toward the head end of, the screw driver, such motion being transmitted to the hubsand disks by the arm ends 21c and 22c to causerotationof the disks in opposite directions with increasingly thicker portions of the disks projecting from.

the head 12. and into the screw slot. When the cumulative width of thedisks is equal to the width of the screw slot, further rotationof the disks is prevented. Thedisks at this point present parallel portions in engagement with the side walls ofthe screw slot thus providing a good fit therewith and allowing the manipulation of the screw by manualrotation of the screw driver through handle 11.

The above described form of screw driver is simple and economical of manufacture, close tolerances not being necessary. If for any reason the blade or adjusting. mechanism require replacement, head 12 is readily removed by bending of the ears 10b inwardly to allow the withdrawal of the head and internal mechanism from the end ofthe shaft 10.

A modified form of screw driver embodying the invention is shown in Figs; 10 to 14. In this form a tubular shaft is provided at one end with a handle 111. At the opposite or head end 112, diametrically opposed-portions of the shaft are constricted inwardly and the portions of the shaft connecting the opposed portions spaced to form an, end having an elongated cross section, as seen in Fig. 13. The blade 113 comprises a pair of disks 113a similar to disks 13 described above except that each disk is provided with a central circular opening 113b and-avsingle radially spaced hole 1130. rotatably carried, by a pin 11.4 which extends through and is carriedby the ,shaft 110 inelongated slots 112a.

Means 115 for rotating the disks, 113a foradjusting; the, thicknesszoftheblade 113comprises a pair of spaced arms-116a and, 116b: each fixedly secured at their'inner. ends to a pin 117 which extends transversely to the shaft 110, adjacent the. handle 111 and. which is loosely received in slots 110a. ating'rnember 118 which-is slidably mounted on the shaft 110. To allow longitudinal movement of the actuating:

member 118 slots 110a are elongated longitudinally of the shaft 110.

At the inner ends, arms 116a and 116b are provided with shoulders 116a.v and 116b respectively which abut the outer end of a helical spring 119 carried within the inner end of the shaft 110. The other end of the spring 119 abuts a pin 111a positioned to compress the spring so that it will bias the. arms 116a.and 116b outwardly.

Arms 116a and 116b are provided atxthe outer ends with laterally, inwardly extending ears- 116a" and 116115. These ears are arranged? to'be received in holes..113c of the disks 113a. Holes 1130 are disposed oppositely equiangularly from the diameter of the disks extending through the thickest and. thinnest portionsthereof 'so that longitudinal movement of the arms 116a. and 116b.with the ears inserted into the holes113'c will cause thedisks Disks 113a are Pin 117 is secured to a tubularactu- '5 to rotate in opposite directions on pin 114. As the ears 11 6a" and 116b" must move in a circular path the outer ends of the arms 116a and 11Gb have transverse motion aswell as longitudinal motion; and clearance between the arm endand the wall of the shaft end 112 is provided as shown.

Spring 119 urges arms 116a and 116b outwardly until pin 117 abuts the outer end of the shaft slot 110a. With the arms in this position the disks are disposed with their thickest portions projecting from the head end of the shaft, as seen in Fig. 11. To allow insertion of the blade 113 into a screw slot, actuating member 118 is moved toward handle 111 against the action of spring 119 until pin 117 abuts the end of slot 110a closest to the handle. Such movement of pin 117 causes the arms 116a and 116b to rotate the disks 113a in opposite directions to the point where their thinnest portions project from the head end 112 of the shaft. Release of the actuating member 118 with the blade inserted into the slot of the screw allows the spring 119 to cause rotation of the disks to the position where the width of the blade is the same as the width of the screw slot.

The outer edge of the head end 112 of shaft 110 is provided with central arcuate flared portions 112b, best seen in Figs. 12 and 13. Flared portions 11212 are adapted to abut the rounded outer surface of a round head screw and transmit longitudinal driving pressures directly from the shaft 110 rather than through the blade 113; when a flat head screw is manipulated the planar outer edge 112a abuts the screw face to act in a similar manner. As the spring 119 constantly urges the disks into their thickest extending relationship the disks tend to grip the side walls of the screw slot and maintain the blade in the slot. As slots 112a in which pin 114 is received is elongated longitudinally of the shaft a variation in the amount of projection of the blade 113 may be effected, thus, accommodation of a wide range of screw slot depths.

When the screw has been withdrawn it may be readily removed from the blade by moving the actuating member 118 toward the handle 111 so as to rotate the disks to a thinner projecting relationship and move the disks longitudinally more fully into the shaft 112. As the screw face is in abutment with the flared end 112b or planar edge 1120 of the head of the shaft 110 the screw will be held while the blade is withdrawn.

In Fig. 15 is shown a modified form of handle and actuating member for use with a screw driver embodying the invention as shown in Figs. to 14. The actuating member and handle of Fig. are particularly adapted for use in electrical applications where insulation of the user from the screw driver blade and shaft is necessary. In this form the handle 211 and actuating member 218 are formed of electrically insulating material. The handle 211 is pro vided with an outwardly opening recess 211a into which a cylindrical projection 218a of member 218 extends. A shaft 210 extends through the actuating member 218 and recess 211a and is fixedly secured to the handle as by having a press fit between its inner end and the'handle. A transversely extending pin 217 to which the inner ends of arms 216a and 21Gb are secured is carried by the projection 218a of the actuating member so as to be within the recess 211a with the handle 211 thus causing the handle to overlie the pin and insulate it from the user. Projection 218a has a readily slidable fit in the recess 211a so that its action may be comparable to the action of actuating member 218a of the screw driver of Figs. 10 to 14. Spring 219 is biased by abutment with ears 210a formed in the shaft 210 adjacent its inner end. The handle and actuating member, thus, completely insulate the user from the shaft and mechanism.

While I have shown and described certain embodiments of my invention it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A tool of the character described, comprising: a tubular shaft; a pair of juxtaposed tapered disks rotatably mounted at one end of said shaft; and means for rotating the disks in opposite directions including a loop element carried in the shaft and having a longitudinally extending mid-portion, a first end pivotally engaging one of the disks at a distance from a plane on which the axis of rotation of the disks lies and which is parallel to the longitudinally extending mid-portion and a second end pivotally engaging the other of the disks at a distance from said plane and in an opposite direction, and a movable element having a portion engaging the mid-portion of said loop element, movement of said element rotating said disks in opposite directions.

2. A tool of the character described, comprising: a tubular shaft; a pair of juxtaposed tapered disks mounted for rotation about a common axis, at one end of said shaft; and means for rotating the disks in opposite directions including a loop element having a longitudinally extending mid-portion, a first end pivotally engaging one of the disks at a distance from a plane on which the axis of rotation of the disks lies and which is parallel to the longitudinally extending mid-portion and a second end pivotally engaging the other disk equidistant from said plane and in an opposite direction thereto, a movable lever having a portion engaging the mid-portion of said loop element and arranged to move said loop element longitudinally, and means yieldingly associated with the shaft to engage the disks and urge them at least partially exteriorly of the shaft.

3. A screw driver of the character described, comprising: a pair of juxtaposed, tapered disks having mutually engaging faces; means for supporting the disks for rotation about a common axis perpendicular to said faces; means for rotating said disks about said axis each in opposite direction and equiangularly; and yielding means urging the disks into an angular position wherein the juxtaposed portions have equal thickness.

4. A screw driver of the character described, comprising: a tubular shaft;.a handle mounted on one end of said shaft; a head mounted on the opposite end of the shaft and having a lateral slot; a pair of juxtaposed, tapered disks rotatably carried within said head; means for rotating said disks in opposite directions including a plurality of loop members having ends eccentrically pivotally engaging said disks, a lever movably secured to the shaft and engaging at least one of said loops for longitudinal movement thereof, and spring means operatively associated with at least one of said loops to urge the disks to a position wherein the thickest portions of the disks project through the head slot; and disk supporting means resiliently mounted in said shaft and arranged to urge the disks out wardly, partially through the head slot.

5. A screw driver of the character described, comprising: a tubular shaft; a pair of facially juxtaposed tapered disks rotatably carried by said shaft and projecting from an end thereof; and means within the shaft and operatively associated with said disks for rotating said disks in opposite directions substantially with means for urging said disks toward one position.

6. A screw driver of the character described, comprising: a tubular shaft; a pair of facially juxtaposed tapered disks carried by said shaft and projecting at least partially from said shaft, said disks each having a hole spaced from the center thereof; a pair of arms in said shaft each having an ear, the ear of one arm received in one disk hole and the ear of the other arm received in the other disk hole; and means for moving said arms to rotate said disks equiangularly in opposite directions.

(References on following page) Eslick Nov. 6, 1951 West Mhr.- 17} 1953' FOREIGN PATENTS Austria- June 10j-1950 Switzerlhnd July 31 1954': 

